Throttle device

Abstract

With the throttle apparatus of the present invention having a throttle valve 30 disposed at an intake passage, a throttle shaft 240 to open and close the throttle valve 30 , a DC motor 51 to drive the throttle shaft 40 , and so on, a second drive means 60 is disposed to exert return force to the throttle shaft 40 only for returning the throttle valve 30 to the rest position. With this structure, since return force is not exerted with a normal operation, load to the DC motor 51 is decreased, and an open-close operation can be preformed smoothly. By returning the throttle valve to the rest position utilizing other means than spring force, load to the motor is decreased, and open-close operation is smoothed.

1. A throttle apparatus, comprising:
 a throttle valve which is disposed at an intake passage of an engine; 
 a throttle shaft which supports said throttle valve to open and close; 
 a first drive means which includes a motor for rotational driving of said throttle shaft; and 
 a second drive means which exerts return force to said throttle shaft so as to return said throttle valve to a specific rest position. 
 
   
   
     2. The throttle apparatus according to  claim 1 , wherein said second drive means comprises a pulley which is fixed to said throttle shaft, a wire which is connected along the circumference direction of said pulley, and an electromagnetic solenoid which drives said wire. 
   
   
     3. The throttle apparatus according to  claim 2 , further comprising an angle detect sensor which detects angle position of said throttle valve, and a control means which controls the driving of at least said first drive means;
 wherein said control means drives said electromagnetic solenoid based on a detect signal from said angle detect sensor and a drive signal of said first drive means. 
 
   
   
     4. The throttle apparatus according to  claim 1 , wherein said second drive means comprises a pulley which is fixed to said throttle shaft, a wire which is connected along the circumference direction of said pulley, and a hand-driven operating lever which drives said wire. 
   
   
     5. The throttle apparatus according to any one of  claims 2  through  4 , wherein said pulley is disposed at the vicinity to which drive force of said first drive means is exerted.